This invention relates to a wait time prediction apparatus for an elevator which predicts the wait times of users waiting in elevator halls, the wait times being information effective for performing an elevator control.
For the purpose of efficiently operating the cages of an elevator as a group and rendering favorable services to passengers, it is important to predict the wait times of the users waiting in elevator halls.
In this regard, it is generally difficult to consider the wait times of the individual users. Therefore, the wait times are often substituted by the periods of time (call registration times) taken between the registrations of calls and the cancellations thereof owing to the arrivals of the cages.
With this measure, however, the same result is produced whether one person or twenty persons is/are waiting in a hall, and the wait times of the individual persons are not considered in the true sense.
It has therefore been proposed to predict the numbers of waiting users at the arrivals of cages and to weight call registration times in correspondence with the numbers of waiting users, so as to utilize the resulting data for the group supervision. An example of the prediction of the numbers of waiting users is disclosed in the official gazette of Japanese Patent Application Publication No. 57-16067, while an example of the weighting with the numbers of waiting users is disclosed in the official gazette of Japanese Patent Application Publication No. 59-24061.
FIG. 5 shows a block diagram in which the above two examples are outlined in combination. Referring to the figure, a service prediction time-calculating device 101 calculates the period of time between the registration of a call and the arrival of a cage, a waiting user appearance rate-setting unit 102 serves to previously set the number of waiting users who appear per unit time, a predictive waiting user number-calculating device 103 predicts the number of waiting users who arrive after the registration of the call, from the outputs of the service prediction time-calculating device 101 and the waiting user appearance rate-setting unit 102, and a waiting user number-detecting device 104 measures the number of waiting users at the registration of the call.
The outputs of the waiting user number-detecting device 104 and the predictive waiting user number-calculating device 103 are added by an adder 105, and the sum result and the output of the service prediction time-calculating device 101 are multiplied by a multiplier 106.
In the arrangement of FIG. 5, it is assumed by way of example that an up call on the first floor be registered. When it is predicted that a cage to serve the call will arrive after 34 seconds, the output of the service prediction time-calculating device 101 becomes "34".
Besides, when it is known that one waiting person appears in 10 seconds in the up direction on the first floor, a rate of 1 (person)/10 (seconds) is set with the waiting user appearance rate-setting unit 102, and the output of this unit becomes "0.1."
It is accordingly presumed that waiting users of 0.1 (person/second).times.34 (seconds)=3.4 (persons) will appear after the registration of the call, so the output of the predictive waiting user number-calculating device 103 becomes 3.4.
Assuming that only one person who has registered the call be the waiting user at the registration of the call, the output of the waiting user number-detecting device 104 becomes 1, and the output of the adder 105 becomes 4.4. That is, it is presumed that there will be 4.4 waiting users at the arrival of the cage. Besides, the output of the multiplier 106 becomes 34.times.4.4=149.6.
This indicates that, in case of performing the group supervision, the up call on the first floor is not handled as 34 seconds but is weighted by 4.4 by estimating the wait times of the individual users. For example, in a system wherein cages are assigned so as to reduce the summation of wait times in the whole building, the wait time on only the first floor becomes 149.6 seconds.
Even with this method, however, the wait times of the individual persons in the true sense are not considered. The reason is that, although the wait time of the person having registered the call is really 34 seconds, those of the other 3.4 persons ought to be less than 34 seconds as these persons arrive later.
In an extreme case, there might be a person who comes to the hall immediately before the arrival of the cage, and the wait time of the person ought to be substantially zero second.
It is desired to make the weighting somewhat smaller with this fact taken into account. Such weighting, however, does not produce a very significant value because the waiting users do not always arrive at equal intervals but they often arrive as groups.
There has been the problem that unless the wait times of the persons other than the person having registered the call can be predicted, the accurate wait times of the individual waiting users are not calculated, making it impossible to perform the group supervision according to which the wait times of the individual users in the true sense become small as the total.